Forcing countries under the United States’ nuclear umbrella to pick a side on disarmament might actually consolidate, rather than undermine, their support for nuclear deterrence.

NATO defence ministerial meeting 2017. ©NATO

By Matthew Harries, Managing Editor of Survival; Research Fellow for Transatlantic Affairs

Extended nuclear deterrence is fundamental to the design of the existing non-proliferation architecture. The non-nuclear-armed members of NATO, Japan, South Korea and Australia are all non-nuclear-weapon states party to the Nuclear Non-Proliferation Treaty (NPT) in good standing with their non-proliferation obligations. Nothing in the NPT forbids either extended nuclear deterrence or NATO nuclear sharing. In fact, extended nuclear deterrence guarantees played a crucial role in persuading several American allies to join the NPT and remain non-nuclear. Although they have different perspectives, countries under the United States’ nuclear umbrella have tended to adopt a moderate stance, supportive of disarmament efforts but falling well short of the uncompromising advocacy of the non-aligned movement. The ban treaty marks an attempt to end this balancing act.

The ban treaty goes much further than simply prohibiting nuclear weapons themselves: it targets deterrence, not just possession or use; it explicitly prohibits nuclear sharing; and it implicitly prohibits a state party from receiving any kind of nuclear deterrence guarantee. It therefore forces umbrella states to pick a side on an issue that they would prefer stayed under the radar. This might actually consolidate, rather than undermine, their support for nuclear deterrence. Yet rejecting the ban treaty outright is politically uncomfortable for many umbrella states, for a variety of reasons, including a general desire to conform to international norms, the opacity and sensitivity surrounding nuclear weapons, and the fact that these are democratic states and thus responsive (albeit to varying degrees) to public pressure.

Read the full report by the European Leadership Network.

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